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dc.contributor.advisorSedimentary basinsen_US
dc.contributor.authorConnell, Sean
dc.date.accessioned2010-06-25T22:02:55Z
dc.date.available2010-06-25T22:02:55Z
dc.date.issued2010-06-25T22:02:55Z
dc.date.submittedMay 2010
dc.identifier.urihttp://hdl.handle.net/1928/10860
dc.description.abstractThe stratigraphic architecture of intracontinental rift basins is defined by a dynamic relationship between depositional belts associated with the basin floor and flanking tributary streams on the piedmont. Spatiotemporal distributions of these deposits are sensitive to basin geometry, subsidence rate, and discharge. Understanding how these depositional belts respond to allogenic forcing is examined using experimental and field approaches. Physical experiments focused on the geomorphic evolution of drainage and the resulting stratigraphic architecture in an asymmetrically subsiding basin based on the form of a simple half graben with four interacting supply points of sediment and water that produced an axial fan and longitudinal channel flanked by transverse fans. Imposition of various combinations of lateral and axial sediment flux showed that the locations and widths of the deposits were controlled by relative sediment discharges and not by the location of the subsidence maximum. Except during the highest of axial sediment discharges in the experiment, the axial drainage was dominated by transverse sources through toe cutting. Footwall fans persisted under conditions of high axial-sediment discharge, aided by topographic inheritance and steeper deposit slopes. The hanging-wall fan responded to changes in sediment discharge more slowly than the footwall. Field comparisons focused on a study of Plio-Pleistocene deposits in the tectonically active Albuquerque Basin of New Mexico. Deposits on the distal hanging-wall ramp onlapped a widespread Miocene erosion surface, burying it by 3.0 Ma. These deposits coarsened after 2.6 Ma, forming a broad sheet of amalgamated channel deposits that prograded into the basin until 1.8 Ma. Axial-river deposition focused near the eastern master-fault system until piedmont deposits prograded away from the basin border after 1.8 Ma. Basin-fill deposition ceased when the axial river began incising shortly after 0.8 Ma. The asynchronous progradation of coarse-grained, margin-sourced detritus may be a consequence of half-graben basin shape that promoted extensive bypass of sediment. Integration of the axial drainage and development of this Plio-Pleistocene sequence likely formed as a result of increased discharge due to late Pliocene and early Pleistocene climatic changes.en_US
dc.description.sponsorshipNational Science Foundation Saint Anthony Falls Laboratory Industrial Consortium, University of Minnesota National Center for EarthSurface Dynamicsen_US
dc.language.isoen_USen_US
dc.subjectNeogene tectonicsen_US
dc.subjectnonmarine stratigraphyen_US
dc.subjectbasin analysisen_US
dc.subjectRio Grande Riften_US
dc.subjectmagnetostratigraphyen_US
dc.subjectgeomorphologyen_US
dc.subjectexperimental stratigraphyen_US
dc.subject.lcshSedimentation and deposition
dc.subject.lcshFluvial geomorphology
dc.subject.lcshGrabens (Geology)
dc.subject.lcshAlbuquerque Basin (N.M.)
dc.subject.lcshRio Grande Rift
dc.titleFluvial sedimentation in continental half-graben basinsen_US
dc.typeDissertationen_US
dc.description.degreeEarth and Planetary Sciencesen_US
dc.description.levelDoctoralen_US
dc.description.departmentUniversity of New Mexico. Dept. of Earth and Planetary Sciencesen_US
dc.description.advisorSmith, Gary
dc.description.committee-memberGeissman, John
dc.description.committee-memberCrossey, Laura
dc.description.committee-memberMeyer, Grant
dc.description.committee-memberPaola, Christopher


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